Magnetic sensing detection system and method

ABSTRACT

A system and method of subjecting a carrier to a magnetism or demagnetism zone either immediately prior to his entrance into a security area, in which goods to be protected are situated, or immediately subsequent to his exit from the security area in order to prevent the removal of the goods from a security area.

[ July 22, 1975 1 1 MAGNETIC SENSING DETECTION SYSTEM AND METHOD [76] Inventor: Emmanuel M. Trikilis, 170

Maplewood Ave., Columbus, Ohio [22] Filed: Dec. 28, 1970 [21] App1.No.: 102,224

Related US. Application Data [63] Continuation of Ser. No. 745,729, July 18, 1968,

[56] References Cited UNITED STATES PATENTS 2,466,251 4/1949 Martin 324/34 3,292,080 12/1966 Trikilis 324/41 Primary Examiner Alfred E. Smith [57] ABSTRACT A system and method of subjecting a carrier to a magflbflndonednetism or demagnetisrn zone either immediately prior to his entrance into a security area, in which goods to [52] US. Cl. 324/41 b protected are ituated, or immediately subsequent [51] hit. CI G01! 33/00 to his exit from the security area in order to prevent Fleld Search 324/34, 340/280, 258 the removal of the goods from a security area.

20 Claims, 5 Drawlng Figures 6 2 SECURITY AREA 3 4 A ggsjlif zzzzzr N 1 13 1 E53 PATHWAY i ----a-- l- L IO '2 E24 DEMAGNETIZERV: l

DEVICE s i 7 BACKGROUND OF THE INVENTION This is a continuation of application Ser. No. 745,729, filed July I8, 1968, and now abandoned.

The unauthorized removal of goods from libraries, department stores, supermarkets, industrial plants, etc., has steadily increased year by year. Present measures for prevention of shoplifting and thefts have proven inadequate and pilfering continues to rise at an alarming rate. Such present measures for controlling pilferage include electronic, mechanical and human surveillance for controlling pilferage. However, these systems have been found economically ineffective for preventing the pilferage of goods.

THE INVENTION This invention is directed to a system and method of preventing the removal of goods which are to remain permanently within a security area. The subject matter of this invention is generally similar in nature to that set forth in my prior application, Ser. No. 412,893, filed Nov. 23, 1964, which has issued into US. Pat. No. 3,292,080 on Dec. 13, 1966.

This invention more specifically relates to a system and method for preventing the pilferage of goods comprising the steps of providing a security area having an entrance pathway and an exit pathway, actively supplying said goods located in the security area with a detectable magnetic field, forming a demagnetizing zone in said entrance pathway, demagnetizing any items having a detectable magnetic field passing through said entrance, forming a magnetic sensing zone in said exit pathway, sensing the detectable magnetic field of any of said goods passing through said exit, and preventing the removal of said goods from the security area.

This specific system and method has been conceived to prevent the possibility of a carrier from entering the security area with an item having a detectable magnetic field that would otherwise inadvertently set off the alarm which would be activated by the magnetic sensor positioned in the exit pathway as the carrier would leave the security area.

Further, this invention contemplates a system and method of preventing the pilferaging of goods, capable of carrying a detectable magnetic field, comprising the steps of providing a security area having an entrance pathway and exit pathway, forming a magnetizing zone in said exit pathway, magnetizing any goods passing through said exit pathway to give the goods a detectable magnetic field, forming a magnetic sensing zone near the egress of the exit pathway, sensing the detectable magnetic field of said goods which pass by said sensing means, and preventing the removal of said goods from the security area.

In this system and method the protected goods are capable of carrying a detectable magnetic field and are magnetized only if the carrier attempts to pass through the exit pathway with the protected goods on his person. This system and method eliminates the possibility of circumventing the prior system due to the fact that the carrier has contact with demagnetizing equipment in the security area itself.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic illustration of this invention;

FIG. 2 is a schematic illustration of a first modification of this invention;

FIG. 3 is a schematic illustration of a second modification of this invention; and

FIG. 4 is a schematic illustration of yet a third modification of this invention.

FIG. 4a is an alternative arrangement of the embodiment shown in FIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 schematically illustrates a security area 1 in which goods 11, which are desired to be protected from being pilfered (hereinafter referred to as protected goods) are arranged. The goods, contemplated by this invention, may include library books, industrial equipment, implements, merchandise or the like which are intended to remain within the confines of the security area and are not to be removed therefrom.

These protected goods are given a detectable magnetic field. If the goods themselves are composed of a ferromagnetic material, they, themselves, may be passed into a magnetic field and, in this way, become magnetized. Alternatively, a piece of material that is already magnetized may be physically attached or secured to the protected goods. The magnetized material, contemplated by this invention, may possess a variety of forms. For example, it may have the physical characteristics of a small thin strip or marker and thereby be easily hidden in or on the protected goods themselves.

It is important that the protected goods themselves or the magnetic material, attached to the goods, carry a strong enough magnetic field that is capable of being detected by any suitable magnetic sensing device, such as of the type described in my aforementioned patent. The protected goods should therefore have a magnetic flux density or a residual magnetic induction which is permanent in the sense that it will not readily dissipate when the goods are left to stand for long periods of time.

The security area 1 is provided with an entrance pathway 2 and an exit pathway 3. In the entrance and exit pathways 2 and 3, respectively, there are arranged one-way door or turnstiles 4 and 5.

A demagnetizer 6, of the type also described in my aforementioned patent, is positioned in the entrance pathway 2. In the exit pathway 3, there is arranged a magnetic sensing device 7. The magnetic sensing device 7 is electrically connected to an alarm 8 and to the turnstile 5 in the exit pathway 3. The movement of the turnstile 5 is such that it will lock in a fixed position only when a magnetic field is sensed by the magnetic sensing means 7.

In the operation of the system shown in FIG. 1, a carrier 10 may pass through the entrance pathway 2 into the security area 1. Once within the security area 1, the carrier has the choice of passing into the exit pathway 3 either with or without being accompanied by the protected goods 11 that carry a detectable magnetic field.

If the carrier 10 chooses the latter, he would pass by the magnetic sensor 7 in the exit pathway 3. Since the carrier carries no detectable magnetic field, the alarm 8 would not be sounded. Further, the turnstile 5 in the exit pathway 3 would not lock because the alarm 8 was not actuated by the magnetic sensor 7. Accordingly, the carrier would be allowed to proceed all the way from the security area 1 through the exit pathway 3 beyond the turnstile 5 without being detained.

However, if the carrier picks up one of the protected goods 11 and proceeds past the magnetic sensor 7, the residual magnetic field emanating from the protected goods would be immediately sensed; the alarm would be sounded; and the turnstile would be automatically locked to prevent the carrier 10 from leaving the exit pathway 3 of the security area 1. In this way the unauthorized attempted removal of the protected goods 11 is made known.

A situation could arise where the carrier 10 might carry into the security area I an article 12 which itself has a detectable magnetic field. Accordingly, if the carrier would attempt to pass through the exit pathway 3 without picking up a protected goods 1 1, the magnetic sensor 7 would still sense the magnetic flux of the article 12 and prematurely activate the alarm 8. To prevent this from occurring the demagnetizer 6, positioned in the entrance pathway 2, is utilized. When a carrier 10, carrying a magnetized article 12, proceeds past the demagnetizer 6, the article 12 is automatically demagnetized. Accordingly, when the carrier 10 passes through the exit pathway 3 only the magnetic field of any of the protected goods 11 can be sensed. In this arrangement, it can be seen that the carrier 10 is automatically magnetically cleaned prior to his entry into the security area.

In the system depicted in FIG. 2, a security area 1 is provided with an entrance pathway 2 and exit pathway 3. In the entrance pathway 2, there is arranged a oneway turnstile 4. In the exit pathway 3, there is positioned a magnetizer 13, a magnetic sensor 7 and a oneway turnstile 5. The magnetizer 13 is situated near the ingress 14 of the exit pathway 3 while the turnstile 5 is located at the egress 15 of the exit pathway 3. The magnetic sensor 7 is arranged intermediate the magnetizer l3 and the turnstile 5. The magnetic sensor 7 is electrically connected to an alarm 8 and also to the turnstile 5.

The protected goods 16, which are located within the security area 1 of the system illustrated in FIG. 2, are not provided with a detectable magnetic field. Instead, each goods 16, either because of its inherent ferromagnetic nature or because it is secured to a piece of magnetizable material, is capable of retaining a magnetic field once the goods 16 are subjected to a magnetic flux density.

Thus, in the operation of the system illustrated in FIG. 2, it can be seen that, if the carrier 10 fails to pick up any goods 16 prior to moving through the exit pathway 3, no alarm would be sounded when the carrier passes the magnetic sensor 7 since there is no magnetic field emanating from the carrier. However, if the carrier picks up one of the protected goods 16 and walks past the magnetizer 13, the protected goods would be given a detectable magnetic field by the magnetic flux density of the magnetizer 13. Accordingly, the magnetic sensor 7 would sense the magnetic field emanating from the goods as the carrier 10 proceeds past the magnetic sensor 7. In order to prevent the carrier 10 from leaving the exit pathway with the protected goods 16 in this situation, the magnetic field of the goods 16 automatically actuates the alarm 8 and locks the tumstile 5 by being sensed by the magnetic sensor 7.

In order to eliminate a possibility of a false reading being made if a carrier walked into the entrance pathway 2 with an article 17 which was capable of retaining a magnetic field or did have a detectable magnetic field, the system of FIG. 2 is modified to the extent of providing a magnetizer 18 near the ingress 20 of the entrance pathway 2 as seen in FIG. 3. At the egress 21 of the entrance pathway 2 a one-way turnstille 22 is also provided. Between each of the magnetizers 18 and the entrance turnstile 22, a magnetic sensor 23 is situated electrically connected to an alarm 24 and to the entrance turnstile 22. As the carrier 10, carrying the article l7 proceeds past the magnetizer 18, the article 17 is magnetized. As soon as the magnetic sensor 23 picks up the magnetic field of the article 17, the alarm 24 is actuated and the turnstile 22 is locked. At this point, the carrier 10 is asked to remove the magnetized article 17 from his possession prior to entering the security area 1. It is thus evident that the system according to FIG. 3 also magnetically cleans the carrier 10 prior to his entry into the security area 1.

FIG. 4 shows still another modified form of the invention. In this embodiment the security area 1 is provided with a pathway 25 which acts as both the entrance and exit pathways depending upon which direction the carrier is moving therethrough. Alternately this form of the invention could be provided with separate and distinct entrance and exit pathways.

A current carrying coil or like device 26 is positioned at the end of the pathway 25 remote from the security area 1. Another current carrying coil or like device 27 is situated at the opposite end of the pathway. Each coil 26 and 27 is capable of producing a magnetic field within the coil to act as either a magnetizer or a demagnetizer, depending upon the type of current that is passed through the coils.

A mangetic sensor 30 is arranged intermediate the coils 26 and 27. Further, a pair of turnstiles, or like devices 28 and 29, are situated in the pathway 25. One turnstile 28 is mounted for rotation between the coil 26 and the magnetic sensor 30 while the other turnstile 29 is arranged between the magentic sensor 30 and the coil 27. Further, the magnetic sensor 30 is electrically connected to both an alarm 31 and to each turnstile 28 and 29.

In order to prevent the removal of the protected goods 32 from the security area 1 in accordance with the system shown in FIG. 4, the operation of the system will be described with relation to an industrial plant.

When the carriers or employees arrive at the security area or plant 1 for work in the morning, the coil 26 is energized to make it act as a magnetizer while the coil 27 is activated to function as a demagnetizer. The turnstile 28 is inactivated thereby allowing it to rotate in either direction while the turnstile 29 is only electrically connected to the magnetic sensor 30 and alarm 31. As the carrier enters the pathway 25, he immediately passes through the magnetizing zone set up by the magnetizing coil 26, thereby megnetizing any articles carried by the carrier that are capable of retaining a magnetic field.

If the carriers article thereby emanates a magnetic field, the magnetic sensor 30 will sense the magnetic field and set off the alarm 31 and simultaneously lock turnstile 29 from rotating as the carrier proceeds along the pathway 25. The carrier, after being relieved of his magnetized article, is allowed only then to proceed past T On the other hand, if the carrier does not possess any articles which either have a detectable magnetic field or are capable of retaining a magnetic field, he would not disturb the system as he passes through the pathway into the security area 1.

At the end of the working day, just prior to the time when the carriers or employees are designed to leave the security area or industrial plant 1, the activity of the coils 26 and 27 is changed such that now the coil 27 becomes a magnetizer and coil 26 becomes a demagnetizer. Further, tumstile 29 is inactivated and tumstile 28 remains only electrically connected to the magnetic sensor 30 and alarm 31.

If the carriers are magnetically clean as they pass from the security area 1 and through the pathway 25, the system again will not be disturbed. However, if the carrier attempts to remove a protected goods 32 which is capable of retaining a detectable magnetic field from the security area 1, the protected goods 32 would become magnetized after passing by the magnetizing coil 27. The magnetic field would thereby be sensed by the magnetic sensor 30 and the carrier would then be prevented from passing the demagnetizing zone from the coil 26 and leaving the pathway 25 since the tumstile 28 would lock after the alarm 31 was sounded.

FIG. 4(a) illustrates an alternative arrangement of the embodiment of FIG. 4 which utilizes a separate entrance pathway 25(a) and exit pathway 25(b). In this arrangement, magnetizers 26(a) and 27(b) are positioned at the ingresses of the entrance and exit pathways for magnetizing any items or goods capable of carrying a magnetic field in order to give them a detectable magnetic field. Demagnetizers 27(a) and 26(1)) are positioned at the egresses of the entrance and exit pathways for demagnetizing any items or goods capable of carrying a magnetic field, and magnetic sensing devices 30(a) and 30(b) are positioned intermediate the magnetizers and the demagnetizers in the entrance pathway and the exit pathway, respectively. The operation of this arrangement is substantially identical to that described in connected with FIG. 4, except that it is simpler because separate entrance and exit paths are used.

It is to be understood that the magnetic sensor may be preset to sense only magnetic fields having predetermined B and H values. For example, since the earths magnetic field is measured at about gauss, the magnetic sensor could be made to sense any field above this background value. Further, the magnetic sensor could be set to sense magnetic fields above those magnetic fields which emanate from small articles ordinarily in the possession of a carrier in his day to day activity.

It is further pointed out that just how sensitive the magnetic sensor of this invention should be in order to effectively pick up the magnetic field is dependent upon the width of the pathway and the strength and duration of the residual magnetic field that emanates from the goods that are to be protected.

Having thus described the invention, with particular reference to the preferred forms thereof, it will be obvious to those skilled in the art to which this invention pertains, after understanding the invention, that various changes and modifications may be made therein without departing from the spirit and scope of the invention, as defined in the claims appended hereto.

1 claim:

l. A method for preventing the pilferage of goods comprising a. providing a security area having an entrance pathway and an exit pathway;

b. actively supplying said goods located in the security area with a detectable magnetic field;

c. forming a demagnetizing zone in said entrance pathway;

d. demagnetizing any items having a detectable magnetic field, passing through said entrance;

e. forming a magnetic sensing zone in said exit pathway;

f. sensing the detectable magnetic field of any of said goods passing through the exit; and

g. preventing removal of said goods from the security area.

2. The method of claim 1 wherein the goods are given a magnetic field by attaching to said goods a permanently magnetized material.

3. The method for preventing pilferage of goods capable of carrying a magnetic field comprising a. providing a security area for said goods having an entrance pathway and exit pathway;

b. forming a magnetizing zone near the ingress of said entrance pathway;

c. magnetizing any items entering said entrance pathway to give said items a detectable magnetic field;

d. forming a magnetic sensing zone near the exit of said entrance pathway;

e. sensing any items passing through said entrance pathway which have a detectable magnetic field;

f. forming a magnetizing zone near the ingress of the exit pathway;

g. magnetizing any goods passing through said exit pathway to give the goods a detectable magnetic field;

h. forming a magnetic sensing zone near the egress of the exit pathway;

i. sensing the detectable magnetic field of said goods which pass by said sensing means; and

j. preventing the removal of said goods from the security area.

4. The method of claim 3, including the step of preventing any items having a detectable magnetic field from entering the security area.

5. In a system for preventing the pilfering of goods within a security area having an entrance and exit pathway, said goods having a detectable magnetic field, comprising a. means for demagnetizing any items having a detectable magnetic field passing through the entrance; and

b. means for sensing the magnetic field of any goods passing through the exit pathway.

6. The system of claim 5 including a means for preventing the removal of the goods having a detectable magnetic field by passing through the exit pathway.

7. The system of claim 5 wherein said demagnetizing means is a current carrying coil.

8. The system of claim 7 including an alarm which is actuated by said magnetic sensing means.

9. In a system for preventing the pilfering of goods within a security area having an entrance and exit pathway, said goods capable of carrying a detectable magnetic field, comprising a. means, positioned near the ingress of the entrance pathway, for magnetizing any items capable of carrying a magnetic field to give said items a detectable magnetic field;

b. means, positioned near the egress of the entrance pathway, for sensing the magnetic field of said items;

c. means, positioned near the ingress of the exit pathway, for magnetizing any goods capable of carrying a magnetic field passing within the exit pathway; and

(1. means, positioned near the egress of the exit pathway, for sensing the magnetic field of goods within the exit pathway.

' 10. The system of claim 9 including means for preventing the entry of items having a detectable magnetic field from passing through the entrance pathway into the security area.

11. The system of claim 10 including means for preventing the removal of said goods having a detectable magnetic field from the exit pathway.

12. The system of claim 11 wherein said magnetizing means are current carrying coils.

13. The system of claim 12 including an alarm which is activated by said magnetic sensing means.

14. The method for preventing the pilferage of goods capable of carrying a detectable magnetic field comprising a. providing a security area for said goods having an entrance pathway and an exit pathway;

b. forming a magnetizing zone at the ingress of said entrance pathway and said exit pathway;

c. forming a demagnetizing zone at the egressses of said entrance pathway and exit pathway; and

d. forming a magnetic sensing zone in the entrance and exit pathway,-intermediate said magnetizing and demagnetizing zones.

15. The method of claim 14 including the step of preventing any articles having a detectable magnetic field from entering the security area after being magnetically sensed in the entrance pathway.

16. The method of claim 15 including the step of preventing the removal of any goods from the exit pathway after being magnetically sensed in an exit pathway.

17. In a system for preventing the pilfering of goods within a security area having an entrance and exit pathway, said goods capable of carrying a detectable magnetic field, comprising a. means, positioned at the ingresses of the entrance and exit pathways, for magnetizing any items or goods capable of carrying a magnetic field to give said items or goods a detectable magnetic field;

b. means, positioned at the egresses of said entrance and exit pathways, for demagnetizing any items or goods capable of carrying a magnetic field; and

c. means, positioned intermediate the magnetizing and demagnetizing means in the entrance and exit pathway. for sensing the magnetic field of said items or goods.

18. The system of claim 17 including means for preventing the entry of items having a detectable magnetic field from passing through the entrance pathway into the security area.

19. The system of claim 18 including means for preventing the removal of protected goods for passing through the exit pathway from the security area.

20. The system of claim 19 including an alarm which is actuated by said magnetic sensing means. 

1. A method for preventing the pilferage of goods comprising a. providing a security area having an entrance pathway and an exit pathway; b. actively supplying said goods located in the security area with a detectable magnetic field; c. forming a demagnetizing zone in said entrance pathway; d. demagnetizing any items having a detectable magnetic field, passing through said entrance; e. forming a magnetic sensing zone in said exit pathway; f. sensing the detectable magnetic field of any of said goods passing through the exit; and g. preventing removal of said goods from the security area.
 2. The method of claim 1 wherein the goods are given a magnetic field by attaching to said goods a permanently magnetized material.
 3. The method for preventing pilferage of goods capable of carrying a magnetic field comprising a. providing a security area for said goods having an entrance pathway and exit pathway; b. forming a magnetizing zone near the ingress of said entrance pathway; c. magnetizing any items entering said entrance pathway to give said items a detectable magnetic field; d. forming a magnetic sensing zone near the exit of said entrance pathway; e. sensing any items passing through said entrance pathway which have a detectable magnetic field; f. forming a magnetizing zone near the ingress of the exit pathway; g. magnetizing any goods passing through said exit pathway to give the goods a detectable magnetic field; h. forming a magnetic sensing zone near the egress of the exit pathway; i. sensing the detectable magnetic field of said goods which pass by said sensing means; and j. preventing the removal of said goods from the security area.
 4. The method of claim 3, including the step of preventing any items having a detectable magnetic field from entering the security area.
 5. In a system for preventing the pilfering of goods within a security area having an entrance and exit pathway, said goods having a detectable magnetic field, comprising a. means for demagnetizing any items having a detectable magnetic field passing through the entrance; and b. means for sensing the magnetic field of any goods passing through the exit pathway.
 6. The system of claim 5 including a means for preventing the removal of The goods having a detectable magnetic field by passing through the exit pathway.
 7. The system of claim 5 wherein said demagnetizing means is a current carrying coil.
 8. The system of claim 7 including an alarm which is actuated by said magnetic sensing means.
 9. In a system for preventing the pilfering of goods within a security area having an entrance and exit pathway, said goods capable of carrying a detectable magnetic field, comprising a. means, positioned near the ingress of the entrance pathway, for magnetizing any items capable of carrying a magnetic field to give said items a detectable magnetic field; b. means, positioned near the egress of the entrance pathway, for sensing the magnetic field of said items; c. means, positioned near the ingress of the exit pathway, for magnetizing any goods capable of carrying a magnetic field passing within the exit pathway; and d. means, positioned near the egress of the exit pathway, for sensing the magnetic field of goods within the exit pathway.
 10. The system of claim 9 including means for preventing the entry of items having a detectable magnetic field from passing through the entrance pathway into the security area.
 11. The system of claim 10 including means for preventing the removal of said goods having a detectable magnetic field from the exit pathway.
 12. The system of claim 11 wherein said magnetizing means are current carrying coils.
 13. The system of claim 12 including an alarm which is activated by said magnetic sensing means.
 14. The method for preventing the pilferage of goods capable of carrying a detectable magnetic field comprising a. providing a security area for said goods having an entrance pathway and an exit pathway; b. forming a magnetizing zone at the ingress of said entrance pathway and said exit pathway; c. forming a demagnetizing zone at the egressses of said entrance pathway and exit pathway; and d. forming a magnetic sensing zone in the entrance and exit pathway, intermediate said magnetizing and demagnetizing zones.
 15. The method of claim 14 including the step of preventing any articles having a detectable magnetic field from entering the security area after being magnetically sensed in the entrance pathway.
 16. The method of claim 15 including the step of preventing the removal of any goods from the exit pathway after being magnetically sensed in an exit pathway.
 17. In a system for preventing the pilfering of goods within a security area having an entrance and exit pathway, said goods capable of carrying a detectable magnetic field, comprising a. means, positioned at the ingresses of the entrance and exit pathways, for magnetizing any items or goods capable of carrying a magnetic field to give said items or goods a detectable magnetic field; b. means, positioned at the egresses of said entrance and exit pathways, for demagnetizing any items or goods capable of carrying a magnetic field; and c. means, positioned intermediate the magnetizing and demagnetizing means in the entrance and exit pathway. for sensing the magnetic field of said items or goods.
 18. The system of claim 17 including means for preventing the entry of items having a detectable magnetic field from passing through the entrance pathway into the security area.
 19. The system of claim 18 including means for preventing the removal of protected goods for passing through the exit pathway from the security area.
 20. The system of claim 19 including an alarm which is actuated by said magnetic sensing means. 